Reserve for Future Policy Benefits and Contractholder Funds - Contractholder funds activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Contractholder funds activity
Balance, beginning of year	$ 857	$ 915	$ 898
Deposits	118	121	126
Interest credited	34	33	34
Benefits	(41)	(34)	(11)
Surrenders and partial withdrawals	(23)	(61)	(21)
Contract charges	(107)	(123)	(114)
Other adjustments	70	6	3
Balance, end of year	$ 908	$ 857	$ 915